ness. 250 By 1874, however, the Clarks had expanded their line and made 

 chronographs for the American observers of the Transit of Venus (q.v. ) . 



The only photographer's objective made by the Clarks that has yet been 

 found — except for the Petzval doublet purchased by Elihu Thomson 

 (q.v.) — belonged to John A. Whipple. In 1863 a visitor to Whipple's 

 Boston studio reported that "His mammoth lens, the work of Alvan Clark 

 of Cambridge, is a sight to see, as are also the views which it takes. 257 Al- 

 though Whipple pioneered in celestial photography, there is no record 

 that his Clark lens was used for anything other than studio portraits. 



Stephen Van Culen White bought Jacob Campbell's (q.v.) tele- 

 scope, observatory, and house in Brooklyn. When the American Astro- 

 nomical Society was founded in 1883, White, as the owner of the largest 

 and finest refracting telescope of any private observer in America, was 

 elected president. 258 Fifteen years later White's telescope was given to 

 Wellesley College ( q.v. ) where it is still in use. 



Williams College, in Williamstown, Massachusetts, added an equa- 

 torial refracting telescope to the equipment of their Hopkins Observatory 

 in 1852. The Clarks, who had yet to prove their mechanical skills, made 

 the optical parts while Jonas Phelps of Troy, New York, made the mount. 

 The 7^ -inch achromatic objective, probably the largest the Clarks had 

 yet made, was deemed excellent. 259 Prof. Albert Hopkins of Williams was 

 so well pleased with the telescope that he recommended a similar one be 

 purchased for Jefferson College (q.v.). 260 The Williams College tele- 

 scope, unchanged except for a new electric motor drive, is still in use. 



In 1890 the principal instrument in C. W. Wilson's private observa- 

 tory in Lynn, Massachusetts, was a 6-inch Clark telescope of "unusual 

 excellence." 261 This is very possibly the telescope which had formerly 

 been owned by Moore ( q.v. ) . 



256 Alvan Clark & Sons to Prof. J. M. Van Vleck, 10 April 1868 (ibid.). 



257 "Photography in Boston," American Journal of Photography, vol. 6 (1863-1864), 

 p. 322. 



258 Scientific American, vol. 48 (1883), p. 64. 



259 Eli as Loomis, Recent Progress of Astronomy (New York, 1856), p. 209. 



260 Albert Hopkins to William C. Bond, 7 February 1859 (letter in Bond Papers, 

 Harvard University Archives). 



261 William C. Winlock, "Progress of Astronomy for 1889, 1890," Annual Report . . . 

 Smithsonian Institution . . . r8go, p. 163. 



109 



